74 Mercury 850 Tilt wiring

[A Full Deck]

Hi,
New to the forum and new to boat engines / wiring. I'm a decent weekend warrior on cars though and I've learned a lot from this site! Thank you all for that. I'm resurrecting a 1974 viking deck boat (new everything basically) and just purchased a rebuilt 74 Merc 850 to go on it. Hopefully, this is an easy question for you.

What are the two wires leading from the starboard side of the outboard clamp? I think it must be some sort of limit switch or possible a kill switch to prevent the motor from starting when tilted too far up, but i have not been able to find any wiring diagram showing it.

Any help is much appreciated!

 

[merc850]

It's a limit switch that you can set to stop the trimming before the motor over revs
you set the small bracket on the side to stop it when you've found the right trim setting. Test it in the water on plane.

 

[A Full Deck]

It's a limit switch that you can set to stop the trimming before the motor over revsView attachment 391837
you set the small bracket on the side to stop it when you've found the right trim setting. Test it in the water on plane.

Perfect! Thank you merc850!

 

[Chris1956]

A lot of those trim limit switches broke 20 years ago. I just jumpered mine (connect the switch wires blue and purple) together, to eliminate the switch, as it needs to be closed to allow trim. The motor will them trim all the way up, unless you release the trim button. Most props will ventilate before the engine trims too much to pump water for cooling.

 

[A Full Deck]

A lot of those trim limit switches broke 20 years ago. I just jumpered mine (connect the switch wires blue and purple) together, to eliminate the switch, as it needs to be closed to allow trim. The motor will them trim all the way up, unless you release the trim button. Most props will ventilate before the engine trims too much to pump water for cooling.

Great info! Thanks Chris1956